| 引用本文: | 郑敏嘉,俞晨欣,余 浩,等.海上风电经不控整流直流并网系统小信号建模及稳定性分析[J].电力系统保护与控制,2025,53(15):158-171.[点击复制] |
| ZHENG Minjia,YU Chenxin,YU Hao,et al.Small-signal modeling and stability analysis of offshore wind farms integrated using diode rectifier based DC transmission systems[J].Power System Protection and Control,2025,53(15):158-171[点击复制] |
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| 摘要: |
| 海上风电场经二极管不控整流(diode rectifier unit, DRU)直流送出系统整流侧DRU不具备控制功能，需要风电机组构网控制实现功率平衡和电压控制。首先建立了采用P-U/Q-的构网型直驱风电以及DRU-MMC混合直流输电系统的线性化状态空间模型，利用阶跃小扰动时域仿真验证了模型的准确性，并分别推导了各自相应的离散状态空间模型。以三风电场经DRU直流输电系统为例，采用离散状态空间建模分析方法构建了全系统小信号模型，通过特征模式分析研究了海上风电经DRU直流并网系统的特征振荡模态及其稳定性。分析结果表明，海上风电经DRU直流并网系统具有分别由系统电气主回路参数主导、风电机侧控制主导、风电场网侧控制与DRU侧耦合作用以及受端MMC控制主导的宽频段特征模式，特别地，多风电场间存在次超同步和低频段控制相互作用模态，其稳定性受相关控制环节参数影响，存在振荡失稳场景。该研究可为认识海上风电场经DRU直流送出系统动态特性，指导海上风电接入电网规划和运行提供分析模型和方法的理论支撑。 |
| 关键词: 海上风电 直流输电 二极管不控整流 特征值分析 小信号稳定性 |
| DOI：10.19783/j.cnki.pspc.241228 |
| 投稿时间：2024-09-10修订日期：2025-03-07 |
| 基金项目:广东省重点领域研发计划项目资助(2021B0101230004)；广东电网公司2023年电力规划专题研究项目资助(031000QQ00230008) |
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| Small-signal modeling and stability analysis of offshore wind farms integrated using diode rectifier based DC transmission systems |
| ZHENG Minjia1,YU Chenxin2,YU Hao1,CHEN Honglin1,ZUO Zhengmin1,YAO Yuwei3,SUN Haishun2 |
| (1. Grid Planning Research Center of Guangdong Power Grid Co., Ltd., Guangzhou 510080, China; 2. School of Electrical
and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, China; 3. China-EU
Institute for Clean and Renewable Energy, Huazhong University of Science and Technology, Wuhan 430074, China) |
| Abstract: |
| In diode rectifier unit (DRU) based DC transmission systems for integrating offshore wind farms, the DRU lacks controllability and hence grid-forming control of wind turbine generators is required for power balance and voltage control of the offshore electrical system. This paper first establishes linearized state-space models of both the grid-forming PMSG wind turbines using P-U/Q- control and the DRU-MMC hybrid DC transmission system. The model’s accuracy is validated through step responses in time domain simulation. Subsequently, a discrete domain state-space model of the whole system is derived. Using a system of three offshore wind farms connected via a DRU-based DC transmission system as an example, a full-system small-signal model is constructed with a discrete state-space approach. Through eigenvalue analysis, the oscillatory modes of the system and their stability are investigated. The analysis results show that there exist wide frequency band eigenmodes attributed to circuit parameters, machine side converter control of PMSG, or interactions between the grid side control of PMSG and DRU, or between the MMC control and AC system. Especially, super- and sub-synchronous frequency as well as low frequency oscillation modes exist due to control interactions among wind farms, whose stability is sensitive to parameters of control designs and may result in unstable oscillation. This research provides theoretical support and analysis methods to understand the dynamic behavior of offshore wind farms connected via DRU-based DC transmission systems, providing guidance for grid planning and operation with offshore wind power integration. |
| Key words: offshore wind farm DC transmission diode rectifier unit (DRU) eigenvalue analysis small-signal stability |
